The invention is related in general to planetary friction drive transmissions, and in particular to three shaft double wedge friction drives.
Friction drives utilize friction force to transmit torque and power. Typically, the friction force within a friction drive is generated at the interfaces of two generally smooth continuous surfaces, which are usually separated by a thick layer of lubricant. Friction drives possess certain features and advantages over other types of drives, such as gear drives. These advantages include smooth and quiet operation, small backlash, high operation, and low manufacturing cost.
Various types of friction drives are known in the art, such as “zero-spin” friction drives. Among “zero-spin” friction drives, the simplest design is perhaps the eccentric planet drive. While eccentric planet drives offer an effective self-loading mechanism known as wedge loading, the eccentric nature of the drive significantly confines its applications to two shaft transmissions. However, power control systems such as variable speed superchargers or turbochargers, utilize three shaft planetary systems with concentric shafts. Therefore, developing a cost effective concentric planetary friction drive is of great importance for these power control systems, particularly those operated at elevated speeds.
Corresponding reference numerals indicate corresponding parts throughout the several figures of the drawings.